Objective To study the impact of a Western diet-type feed on biological indicators and histopathology in APOE^{- / -} mice. Methods Forty-eight female and 48 male APOE^{- / -} mice, and 48 female and 48 male C57BL/ 6J mice were divided into eight breeding groups: APOE^{- / -} breeding feed group, APOE^{- / -} Western dietary feed group, C57BL/ 6J breeding feed group, and C57BL/ 6J Western dietary feed group (24 male and 24 female mice per group). Mice were fed the respective diets from 3 weeks until the end of the experiment at 20 weeks. After the experiment, serum was collected for measurement of biochemical indicators. Aortas were removed for oil red O staining and gross examination and the aorta root was paraffin sectioned and stained with hematoxylin and eosin. Results A Western diet did not significantly increase body weight in APOE^{- / -} mice, but did significantly improve the blood lipid index and total cholesterol, low-density lipoprotein,and high-density lipoprotein levels, and promoted the formation of atherosclerotic plaques. Male mice were suitable for modeling gross aortic plaques while female mice were suitable for modeling aortic arch root plaques. Conclusions A Western diet can promote atherosclerosis in APOE^{- / -} mice, increase the aortic plaque area ratio, shorten modeling time,and improve modeling uniformity.